President Donald Trump is using targeted Facebook ads to reassure supporters that he still plans to build the border wall after his recent public comments caused many to question whether he would keep his promise.

"There's been a lot of noise and a lot of rumors," reads the text of a Facebook ad from Trump's personal Facebook page that was targeted to specific users in recent days. "....WE WILL BUILD A WALL (NOT A FENCE) ALONG THE SOUTHERN BORDER OF THE UNITED STATES..." The ad concludes with a pitch for donations.

That all-caps declaration is in contrast to a widely discussed tweet last week in which the president said the wall was already underway "in the form of new renovation of old and existing fences and walls." That led supporters such as Fox & Friends' Steve Doocy to ask, "Has the wall almost become symbolic?"

The personal Facebook page of Vice President Mike Pence is also running a version of the ad. One difference between the Pence and Trump ads is the VP's refers to "Fake News media," while Trump's calls out the "mainstream media." Both ads include a dig against "liberals in Congress."

A White House spokesman told BuzzFeed News the ads are being run by the Trump campaign, and referred all questions to it. The Trump campaign did not respond to emails or phone messages about the ads.

The ads are not visible on the timelines of the Trump or Pence Facebook pages. They are, therefore, so-called "dark post ads" because they can only be seen by people the campaign chose to target with the message. This is the same type of ad Facebook recently acknowledged was purchased by a Russian troll factory in order to target Americans during the election. That revelation has caused lawmakers such as Sen. Mark Warner to discuss the need to regulate online political ads.

"An American can still figure out what content is being used on TV advertising. ... But in social media there's no such requirement," Warner said, according to CNN.

The Trump and Pence ads also highlight how politicians can use targeted ads to push a message to supporters that walks back or contradicts a public statement.

"If candidates (and outside groups) can say different things to different voters, it is harder to hold them accountable for campaign promises," Erika Franklin Fowler, director of the Wesleyan Media Project, which tracks political ads aired on broadcast television during state and federal elections, previously told BuzzFeed News.

These ads are also an example of how targeting can miss its mark. Nancy Levine, an author of books about pugs, was shown both ads in her News Feed and provided them to BuzzFeed News. She said she is far from a Trump supporter or potential donor.

"I wonder how was I targeted? Most everything I post on FB is of the 'Fuck Trump' variety," Levine said.

At BuzzFeed News' request she visited the ad preferences page on her Facebook profile, where anyone can view the interests the social network has identified for a user based on their behavior on and off the platform. To her surprise, Levine discovered her interests included "Donald Trump" and "Conservatism," as well as other outliers such as "Chainsaw."

"I don't even rake my leaves, much less use a chainsaw," she said.

Craig Silverman is a media editor for BuzzFeed News and is based in Toronto.